shader: Initial recompiler work

src/shader_recompiler/frontend/maxwell/instruction.h

@@ -0,0 +1,62 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/bit_field.h"
+#include "common/common_types.h"
+#include "shader_recompiler/frontend/ir/flow_test.h"
+
+namespace Shader::Maxwell {
+
+struct Predicate {
+    Predicate() = default;
+    Predicate(unsigned index_, bool negated_ = false) : index{index_}, negated{negated_} {}
+    Predicate(bool value) : index{7}, negated{!value} {}
+    Predicate(u64 raw) : index{static_cast<unsigned>(raw & 7)}, negated{(raw & 8) != 0} {}
+
+    unsigned index;
+    bool negated;
+};
+
+inline bool operator==(const Predicate& lhs, const Predicate& rhs) noexcept {
+    return lhs.index == rhs.index && lhs.negated == rhs.negated;
+}
+
+inline bool operator!=(const Predicate& lhs, const Predicate& rhs) noexcept {
+    return !(lhs == rhs);
+}
+
+union Instruction {
+    Instruction(u64 raw_) : raw{raw_} {}
+
+    u64 raw;
+
+    union {
+        BitField<5, 1, u64> is_cbuf;
+        BitField<0, 5, IR::FlowTest> flow_test;
+
+        [[nodiscard]] u32 Absolute() const noexcept {
+            return static_cast<u32>(absolute);
+        }
+
+        [[nodiscard]] s32 Offset() const noexcept {
+            return static_cast<s32>(offset);
+        }
+
+    private:
+        BitField<20, 24, s64> offset;
+        BitField<20, 32, u64> absolute;
+    } branch;
+
+    [[nodiscard]] Predicate Pred() const noexcept {
+        return Predicate{pred};
+    }
+
+private:
+    BitField<16, 4, u64> pred;
+};
+static_assert(std::is_trivially_copyable_v<Instruction>);
+
+} // namespace Shader::Maxwell